An androgen responsive cells strain of chick comb fibroblasts has been established in culture. Cells were obtained from combs of 1-2 day old white Leghorn cockerals and cultured in Dulbecco's modified Eagle medium which contained 10% fetal calf serum and 7 g/l glucose. The cells require serum but not androgens for growth. In the presence of androgens, growth rate and incorporation of labeled precursors into protein and RNA are increased in exponentially growing cells, but not in confluent cultures. Androgens exert these stimulatory effects in a dose-dependent fashion. Early biochemical events stimulated by androgens include increased ornithine decarboxylase activity and increased cyclic AMP levels following 4 hours of androgen treatment. Androgen stimulation of connective tissue formation was seen 48 hours after treatment via increased collagen and glycosaminoglycan synthesis. Metabolism of androgens by chick comb cells was extensive. These studies are the initial characterization of a new strain of androgen responsive cells.